Point Compare

[cbnelson]

I get a fair number of messages that drawing points and crd points don't match. When I review the points the crd file reports negatives of the coordinate values in the drawing.

DWG Point# DWG Northing DWG Easting DWG Elevation Delta North Delta East Delta Elevation

107 5101.44 5159.92 7.37 -5101.4400 -5159.9200

It seems cosmetic because when I export the points there are no negative numbers.
It is a little worrisome thinking I may give a crew bad coordinates when I am rushed.
Any one else have this happen?

[gskelhorn]

I get a fair number of messages that drawing points and crd points don't match...

DWG Point# DWG Northing DWG Easting DWG Elevation Delta North Delta East Delta Elevation

107 5101.44 5159.92 7.37 -5101.4400 -5159.9200

My interpretation of this is you are comparing points that have values with ones that have coordinate values of 0.000 0.000
Since the comparison is using a DWG then check if there are points drawn at (0.000,0.000), possibly on a layer that is turned off or frozen?

[SRLEONE]

I also have this feature turned on and get nervous, too, when there are differences. As far as I can tell, this is a difference between the location and elevation of the CAD point versus the CRD/survey point. No clue why they are not automatically the same. I suspect it has something to do with whether or not the "Locate on Z axis" checkbox is checked on the Locate Point dialog box during point creation. You know how you might use Interpolate Along Entity to create a whole bunch of 5'BC offsets and elevate them later? That will make the CAD point (essentially the symbol) be at 0.00' elevation, and that does NOT get changed (consistently) when you Edit Point Attributes later to make it a real stake point. It's frustrating and, as the OP's question shows, leads to doubt and mistrust of the software. Wish it could be gone away with!

Does anyone have an explanation for this phenomenon and maybe how to prevent it from happening?

[gskelhorn]

SRLEONE wrote:
I suspect it has something to do with whether or not the "Locate on Z axis" checkbox is checked on the Locate Point dialog box during point creation.

I believe you are on the right track. I almost always work with Locate on Z axis turned off. The result is my points in the drawing have the Z value attribute displayed as the actual elevation and the block inserted in the drawing with a 0.00 Z value. the point comparison between the drawing and coordinate database are done using the point insert CAD X and Y values but the Z comparison is done using the Z attribute value and the coordinate file Z value. This will always produce differences in the Z equal to the Z value rounding at the precision you use for the displayed elevation in the drawing points.

I typically have the sensitivity of the elevation comparison set to 1/2 the displayed precision. i.e. When my drawing has points plotted with displayed elevation prevision set to 0.01 then the comparison elevation difference reported must be greater than 0.005 for me to want to see them.

This automatic comparison is a feature that increases my confidence in the integrity of my drawings.

(edited to clarify the point Z attribute display the actual elevation)

[SRLEONE]

It is terrifying, however, when the XY is different. Numbers get erased and reused in the CRD. And the point map needs to reflect those changes. When the software tells me that the drawing did not update with the CRD, I get feisty! And then when I zoom to the point, double click it and choose the File location (which I truly wish would get changed to say "CRD") and it updates... and then next time I open it it still shows up on the point comparison report... makes me see fiery red pinwheels LOL

I go back and forth about how useful the feature is.

[gskelhorn]

It is terrifying, however, when the XY is different. Numbers get erased and reused in the CRD. And the point map needs to reflect those changes.

Yes. Here's a little off-the cuff rambling...

My thoughts are many aspects of working with the complex hardware / software systems and workflows we use today have potential pitfalls. I have tried many products and found potential for us to make unnoticed errors in all. The heavily integrated / automated systems and more manual processes each have merits and potential to miss some side-effect or manually triggered update.

The key for me is to develop and test a workflow for each task and discover the ways the errors can be introduced then find ways to detect them. In Carlson Civil and Survey I use drawing vs CRD file point comparisons a lot. There are also the CFUHISTORY, Update Drawing from CRD file and Update CRD file from Drawing commands that I make frequent use of.

I do not work with object linking within Carlson set to create a link between points and the CRD file, linework with points , nor labels with linework. The Object Links were not something I was comfortable relying on at the time or Carlson adoption and cannot comment on recent versions since I have not tested again with each update.

My workflow using points is heavily based around field-to-finish and point groups. There are parts of my workflow that do create duplicate point entities in the drawing and I do find it annoying so my solution has been to redraw the point set I have been working with using F2F set to delete the old ones before drawing new ones. This is quick and gives me confidence all points in the drawing are as my CRD file has recorded. If you don't use F2F then you could do use LPOINT (menu Points | Draw-Locate Points) with Duplicates option set to Erase and Redraw

One of my related concerns has been increasing my personal confidence in the location of lines and arcs intended to connect points. My most common workflow uses CG-Survey commands to draw the lines and arcs I want related to CRD file points together with frequent use of the CG_REFRESH command to redraw as points are updated. There is a weak point in this flow when I copy a drawing to a different project or want the graphics to relate to a different CRD file. For these cases I use the CFU | Point Entity CRD File Links Manager for the points and custom created LISP routine to alter the CRD file link in the line and arc entity extended data. Could be better way but this was what I found several years ago and stuck with it.

These forums are pretty quiet. i wish there was more posting on them. I have found Carlson support open to addressing issues and for providing helpful advice. I recommend also sending an email to support about anything you perceive as significant for your work.